Unilateral retinitis pigmentosa in children

Retinitis pigmentosa (RP) is a group of rare inherited retinal disorders characterized by diffuse progressive degeneration of the retina that typically presents bilaterally. Unilateral RP has not often been reported in children. We present a series of cases that illustrate discrimination between unilateral and asymmetric disease and between dystrophy and acquired degeneration.

Four patients (9-15 years of age; 3 females) were referred to our institution for possible unilateral RP based on fundus appearance and unilateral symptoms. All underwent full-field electroretinography (ERG), spectral domain optical coherence tomography (SD-OCT), widefield and color fundus photography, and fundus autofluorescence (FAF) imaging. Genetic testing and a vitamin and essential fatty acids panel were also conducted in 1 patient.

Unilateral retinal degeneration was confirmed in 2 patients, whose fellow eyes showed no abnormalities on ERG or imaging. The other 2 patients were found to have highly asymmetric retinal degeneration based on ERG, wide-angle images, and repeated examinations (range, 0.3-9.8 years). Genetic testing and blood testing in 1 unilateral case were negative.

Childhood-onset "unilateral RP" remains a difficult and uncertain diagnosis. ERG testing and longitudinal and widefield fundus examination are necessary to exclude asymmetrical disease. Although unilateral degeneration may exist in some children, its inherited or acquired etiology remains poorly understood.